JP3504308B2 - Adjusting the paper feed capacity of the paper feed roll for electronic copiers - Google Patents

Description

BACKGROUND OF THE INVENTION [0001] BACKGROUND OF THE INVENTION This invention relates to how to adjust the paper feed capacity sheet feed roller for adhering paper passed through the silicone oil once electronic copier It is. [0002] In general, rubber roll materials are isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber ( CR), nitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPM, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM,
ANN), epichlorohydrin rubber (CO, ECO),
Various rubber materials such as polysulfide rubber (T), urethane rubber (U), fluorine rubber (FKM, FZ), silicone rubber (Q), and polynorbornene rubber can be used.
What is required of the rubber roll for paper feeding is a paper feeding ability for reliably feeding paper. Therefore, to date, ethylene-propylene rubber and polynorbornene rubber, which have a high coefficient of friction with paper, which is an index of paper feeding ability, have been mainly used to obtain paper feeding reliability. [0003] In an electronic copying machine, there is a process of toner fixing in which a paper on which toner has passed, which has passed through a developing unit, is sandwiched between nip portions of a pair of heating rolls. Here, a phenomenon occurs in which the paper is wound around the roll mainly due to the fusion of the fused toner to the fixing roll. At present, a fixed amount of silicone oil is constantly supplied to the surface of the fixing roll to prevent this. As a result, the silicone oil is transferred to the surface of the paper. In recent years, mechanisms such as double-sided copying and an automatic paper feeder have been rapidly spread in electronic copying machines. In these mechanisms, the paper once passed through the fixing unit is conveyed, so that the paper with the silicone oil adhered to the surface must be fed by a roll. However, if such paper is fed by a general synthetic rubber roll, slip failure occurs due to silicone oil, and the paper cannot be fed normally. Further, in a color copy that has become widespread in recent years, the temperature of a fixing roll is further increased due to toner coloration, and the toner adhesion is strong. Therefore, the amount of silicone oil applied is larger than that of a black and white copy. As described above, especially in the case of color copying, even if the conventional ethylene-propylene rubber or polynorbornene rubber is used, there is a problem that the paper feeding ability is not stable over time. In addition, there are various types of paper feed rolls, such as "automatic document feeder", "manual feeder", "double-sided copy tray", and "normal tray". The probabilities are also different, and the required paper feed capacity of the silicone oil-coated paper varies. There has been a demand for a method of making fine adjustments to meet such requirements. SUMMARY OF THE INVENTION The present inventors have solved the above-mentioned problems, and in order to provide a roll with a stable paper feed ability with time according to the required paper feed capacity, a silicone oil As a result of various studies on silicone rubber, based on the policy of preventing silicone oil from accumulating on the roll surface by absorbing
It has been found that the object can be achieved by adjusting the degree of crosslinking, and the present invention has been accomplished. That is, the present invention has solved the above-mentioned problems, and the present invention relates to a silicone rubber material for a paper feed roll containing 100 parts by weight of an organic polysiloxane raw rubber containing 0 to 0.5 mol% of a vinyl group. A blend containing 20 to 60 parts by weight of reinforcing silica is prepared in advance, and 100 to 200 parts by weight of an organopolysiloxane raw rubber having a vinyl group content of 0 to 0.5 mol% is mixed with the mixture to obtain an average vinyl. Group content 0.05-0.2
By adjusting the mol%, it relates to <br/> how to adjust the feeding ability of the silicone oil coated paper of the silicone rubber sheet feed roller. [0006] As described above, the feeding ability of the silicone oil-coated paper required for the feeding roll is also different.
In order to cope with this, the amount of vinyl groups (density of vinyl groups) involved in vulcanization was adjusted in the conventional organopolysiloxane raw rubber before filling with reinforcing silica. Must be included, making the production very laborious. Also, it is impossible to make subtle adjustments to meet the demands. In contrast,
According to the invention, this manufacturing problem has been solved, so that adjustments can be made to meet the requirements. Hereinafter, the present invention will be described in detail. In the present invention, the vinyl group-containing organopolysiloxane raw rubber to be used is characterized in that the content of vinyl groups (density of vinyl groups) is 0 to 0.5 mol% in all side chain organic groups. Further, a feature of the present invention is that the composition is divided into two types, and the density of the vinyl group is adjusted by mixing the two types. More preferably, the density of the vinyl group is 0.2 to 0.5 mol%. The other is 0-0.2mol
%. Reinforcing silica is added to either of them, but either of a high vinyl group density and a low vinyl group density is optional. The average vinyl group density of the blend obtained after the mixing is set at 0.05 to 0.2 mol% depending on the mixing ratio, and more preferably 0.07 to 0.2 mol%.
Range. If the amount is less than 0.05 mol%, the compression strain characteristics deteriorate, and at the same time, the friction coefficient decreases.
If the amount is more than 1%, the silicone oil absorbing ability becomes insufficient. In the present invention, as the reinforcing silica filler to be added to one of the compounds, known ones can be used, but the compounding amount is 20 to 60 parts by weight based on 100 parts by weight of the vinyl group-containing organopolysiloxane raw rubber. It is preferable that the type of silica is fumed silica. This is because it is known that the use of fumed silica increases the coefficient of friction as compared with those using wet silica. When further blending the vinyl group-containing organopolysiloxane raw rubber with the above-mentioned vinyl group-containing organopolysiloxane raw rubber blended with a reinforcing silica filler, the amount of the reinforcing silica compounded in the blend obtained after mixing is 10 to 20 parts by weight. It is preferable to adjust as follows. The compounding amount is 10
When the amount is less than the weight part, the reduction of the coefficient of friction and the strength is out of the general range as the paper feed roll,
If the amount exceeds 0 parts by weight, the hardness of the rubber increases, the nip width under a constant load decreases, and the paper feeding ability decreases. Regarding the mixing of the reinforcing silica filler, it is also optional to add a known dispersant or the like in order to improve the dispersion in the vinyl group-containing organopolysiloxane raw rubber. In the present invention, an organic peroxide such as benzoyl peroxide, bis-2,4 is used as a curing agent (vulcanizing agent) for curing the silicone rubber composition.
-Dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis-t-butylperoxyhexane, etc., and more preferably non-acyl It is a system organic peroxide. This is because by using a non-acyl organic peroxide, a roll having good compression strain characteristics can be obtained, and the coefficient of friction with paper tends to increase. The amount of the organic peroxide to be added may be an appropriate amount for obtaining sufficient physical properties of the vulcanized rubber, but is usually 0.3 to 2 parts by weight based on 100 parts by weight of the vinyl group-containing organopolysiloxane raw rubber. Part range. In the compounding method of the silicone rubber compound according to the present invention, first, the above-mentioned organopolysiloxane raw rubber having a vinyl group, a reinforcing silica filler and a dispersing agent which is added as required are mixed uniformly. Things. The method for mixing may be a known method for producing a silicone rubber compound, and may be, for example, uniformly kneaded with a pressure kneader, a Banbury mixer, a mixing roll, a planetary mixer, or the like. A predetermined vinyl group-containing organopolysiloxane raw rubber may be further mixed with the obtained composition with a mixing roll or the like to adjust the composition to a desired average vinyl group density. The organic peroxide as a curing agent may be uniformly kneaded using a normal mixing roll immediately before molding. In addition, at the time of this kneading, it is possible to freely color by adding a pigment to the composition. Next, the above compound is molded into the outer peripheral portion of the core by heating under pressure. The method is a method which can be cured by heating under pressure, such as press molding, injection molding, transfer molding. A method may be used. If necessary, secondary vulcanization may be carried out by hot air vulcanization at 150 to 250 ° C. for 1 to 24 hours to remove organic peroxide decomposition residues and low molecular siloxane. Furthermore, when applying these molding methods, the core of the roll is set in a mold in advance, and the composition is integrally molded on the outer periphery thereof,
A method in which only the composition is molded in advance and then pressed into and adhered to the roll core can be appropriately selected. Further, as the finish of the roll shape, the surface can be polished by using an ordinary cylindrical grinder or the like. Next, embodiments of the present invention will be described. (Example 1) Two types of dimethylpolysiloxane raw rubbers having a side chain vinyl group content of 0 and 0.5 mol%, both ends of which are blocked with a trimethylsilyl group, were mixed with a mixing roll, and the mixing ratio as a whole was determined. The dimethylpolysiloxane raw rubber was adjusted so that the vinyl group content was 0.21 mol%. To 100 parts by weight of the dimethylpolysiloxane raw rubber, 30 parts by weight of fumed silica and an appropriate amount of a dispersant were added and kneaded with a kneader. To 100 parts by weight of the composition obtained above, a vinyl group content of 0.21, 0.13, 0.0
5, 0, and 0 mol% of dimethylpolysiloxane raw rubber were added in 100, 100, 100, 133, and 203 parts by weight, respectively, and kneaded uniformly with a mixing roll. Further, as a vulcanizing agent, 2,5-dimethyl-2,5-bis-t-
0.8 parts by weight of butyl peroxyhexane was similarly added with a mixing roll, and the mixture was uniformly kneaded by a usual method to obtain a composition. [0013] This is divided into 0.6 mm thickness by two rolls, filled in a mold having a 0.5 mm thick metal frame, and cured by heating and pressing to form a 0.5 mm thick sheet. A molded product was obtained. After secondary vulcanization of the obtained molded product, width 30mm,
It was cut into a length of 80 mm to produce a strip-shaped test piece.
Dimethyl silicone oil (300 cS)
Was applied at 0.60 mg / cm ² , and the relationship between the elapsed time after application and the friction coefficient was examined. The result was as shown in the graph of FIG. In addition, JIS K6301 was used for each of the above compositions.
The properties shown in Table 1 were obtained by examining the physical properties after vulcanization according to the above. Example 2 Each of the compositions obtained in Example 1 was filled in a mold having a cavity processed into a cylindrical shape, cured by heating and pressure, and then polished with a cylindrical grinder. ,
A cylindrical molded product having an inner diameter of 9 mmφ and an outer diameter of 20 mmφ was obtained.
This was pressed into a stainless steel shaft having an outer diameter of 10 mm to obtain a roll sample. Table 1 shows the results of measuring the coefficient of friction of these roll samples. [Table 1] According to the method for adjusting the paper feeding capacity of the present invention, it is possible to easily obtain a paper feeding roll which meets various required characteristics of silicone oil absorption capacity and is well balanced with a friction coefficient. Can be. Also, silicone rubber is
The paper feed roll thus obtained has high stability against the environment such as ozone, high temperature and low temperature, and also has excellent environmental resistance, and thus the present invention has high industrial value.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the relationship between the elapsed time after application of dimethyl silicone oil to a test piece and the friction coefficient in Example 1.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshikasa Kasahara 300-5 Toyohara, Motohara, Kagawa, Kodama-gun, Saitama Prefecture Shin-Etsu Polymer Co., Ltd. 300-5 Motohara Toyohara Shin-Etsu Polymer Co., Ltd. Kodama Plant (56) Reference JP-A-61-238075 (JP, A) JP-A-3-192036 (JP, A) JP-A-7-125101 (JP, A) A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29D 31/00 B65H 5/06 B65H 27/00 F16C 13/00 G03G 15/00 510

Claims (1)

(57) [Claim 1] In a silicone rubber material for a paper feed roll, reinforcing silica 2 is added to 100 parts by weight of an organopolysiloxane raw rubber containing 0 to 0.5 mol% of a vinyl group.
A composition containing 0 to 60 parts by weight is prepared in advance, and 100 to 200 parts by weight of an organopolysiloxane raw rubber containing a vinyl group of 0 to 0.5 mol% is mixed with the mixture to adjust the average vinyl group content. 0.05-0.2mol
%. A method for adjusting the feeding capacity of the silicone oil-coated paper of the silicone rubber for the feeding roll, wherein the feeding rate is adjusted to%.